Basis Definition and 1000 Threads

  1. C

    Prove coordinate vectors are unique for given basis

    Homework Statement Prove that the coordinates of a vector v in a vector space Vn are unique with respect to a given basis B={b1,b2,...,bn} Homework Equations The Attempt at a Solution not sure at all what to do with this
  2. C

    Problem in constructing Matrix representation in |↑↓> basis

    If I want to derive the matrix representation for operator Q in the |S1=1/2 ,m1> |S2=1/2 ,m2 > basis, where |Si,mi> are common eigenstates of S2 , Si,z for the ith particle. And I do it in this way: <↑↑|Q|↑↑> <↑↑|Q|↑↓> <↑↓|Q|↓↑> <↑↑|Q|↓↓> <↑↓|Q|↑↑> <↑↓|Q|↑↓> <↑↓|Q|↓↑> <↑↓|Q|↓↓> ...
  3. B

    Linear Algebra: does it form a basis?

    Homework Statement See attachment. The Attempt at a Solution I already did parts i and ii (correctly, I hope). On part iii I found 2 linearly independent elements to be: t+1, t^2 - 1. However, I don't understand how to show that these form a basis of W. Because W is a subspace of P2, and P2...
  4. E

    Understanding Basis for Solving Linear Algebra Problems

    Hey guys There are so many of these damn "Find a basis" questions and I can't get any of them because we never directly learned how...or she never showed us in class...my final exam is tomorrow. Here are some examples of questions: http://184.154.165.18/~devilthe/uploads/1323453294.png...
  5. V

    Finding orthonormal basis for the intersection of the subspaces

    Homework Statement Homework Equations can someone help me to solve this problem? The Attempt at a Solution I couldn't even approach
  6. A

    Is {u+v+w, v+w, w} Also a Basis for V?

    Let u,v,w\in V a vector space over a field F such that u≠v≠w. If { u , v , w } is a basis for V. Prove that { u+v+w , v+w , w } is also a basis for V. Proof Let u,v,w\in V a vector space over a field F such that u≠v≠w. Let { u , v , w } be a basis for V. Because { u , v , w } its a basis...
  7. O

    Values for which a set of vectors form a basis of Rn

    Homework Statement For what value(s) of λ is the set of vectors {(λ^2-5, 1, 0), (2, -2, 3), (2, -3, -3)} form a basis of ℝ^3Homework Equations in order for a vector to form a basis it has to span R3 and the set has to be linearly independent.The Attempt at a Solution i tried doing row...
  8. F

    Is the Set of Functions f[sub k] a Basis for the Vector Space V?

    Homework Statement Let S be any non-empty set, F be a field and V={ f : S -> F such that f(x) = 0 } be a vector space over F. Let f[sub k] (x) : S -> F such that f[sub k] (x) = 1 for k=x, otherwise f[sub k] (x) = 0. Prove that the set { f [sub k] } with k from S is a basis for the vector space...
  9. L

    Change for position to energy basis

    Homework Statement Give expressions for computing the matrix elements Xmn of the matrix X representing the position operator X in the energy basis (using eigenvectors of the Harmiltonian operator) Also told to consider the example of the harmonic oscillator where energy eigenvalues are...
  10. H

    [Linear Algebra] Basis, Linear Inependence

    Homework Statement Homework Equations The Attempt at a Solution 2) No clue.
  11. M

    Relationship of Basis to Dual Basis

    If we're working in R^n and we consider the elements of a basis for R^n to be the column vectors of an nxn invertible matrix B, then what is the relationship between B and the matrix whose row vectors represent elements of the corresponding dual basis for R^n*? My guess, which Wikipedia helped...
  12. F

    Find Basis for Span: \vec{a_{1}} to \vec{a_{4}}

    I don't wan't a solution I wan't only instructions how to solve this problem: Find a basis for the span: \vec{a_{1}}=(1,\,-1,\,6,\,0),\,\vec{a_{2}}=(3,\,-2,\,1,\,4),\,\vec{a_{3}}=(1,\,-2,\,1,\,-2),\,\vec{a_{4}}=(10,\,1,\,7,\,3)
  13. Z

    Schools What to do about grad school? What does an engineer do on a day to day basis?

    I’m currently a physics/math major. I work very hard and am proud of my 4.0 GPA. However, as my peers and professors begin to talk about grad school I realize I don’t have a clue what I'm supposed to do. My goal is to go to Penn State for an advanced degree in some type of engineering or...
  14. L

    Inner product space and orthonormal basis.

    Homework Statement Assume the inner product is the standard inner product over the complexes. Let W= Spanhttp://img151.imageshack.us/img151/6804/screenshot20111122at332.png Find an orthonormal basis for each of W and Wperp.. The Attempt at a Solution Obviously I need to use Gram-Schmidt...
  15. V

    A problem on finding orthogonal basis and projection

    Use the inner product <f,g> = integral f(x) g(x) dx from 0 to 1 for continuous functions on the inerval [0, 1] a) Find an orthogonal basis for span = {x, x^2, x^3} b) Project the function y = 3(x+x^2) onto this basis. --------------------------------------------------------- I know the...
  16. V

    A problem on finding orthogonal basis and projection

    Use the inner product <f,g> = integral f(x) g(x) dx from 0 to 1 for continuous functions on the inerval [0, 1] a) Find an orthogonal basis for span = {x, x^2, x^3} b) Project the function y = 3(x+x^2) onto this basis. --------------------------------------------------------- I know the...
  17. V

    Is the ISW Hamiltonian Diagonal in the Energy Basis?

    Homework Statement Find the matrix elements of the Hamiltonian in the energy basis for the ISW. Is it diagonal? Do you expect it to be diagonal? Homework Equations H=\frac{p^2}{2m}+V \frac{d}{dt}\langle Q \rangle = \frac{i}{\hbar} \langle[\hat H, \hat Q] \rangle + \langle...
  18. A

    Finding the basis of a null space

    Homework Statement The matrix is: -2 -2 -4 4 -1 1 2 -2 -1 0 -3 0 -4 1 -7 -2 I know the dimensions for the null space are 2 Homework Equations I know that to find the basis for a null space Ax=0, so I row reduced it and I got 1 0 3 0 0 1 5 -2 0 0 0 0 0 0 0 0 The Attempt...
  19. M

    What is the basis for a plane perpendicular to 3x + 2y − z = 0?

    Homework Statement Let W be the plane 3x + 2y − z = 0 in ℝ3. Find a basis for W perpendicularHomework Equations The Attempt at a Solution I thought a basis for this plane could be generated just by letting x=0 and y=1, finding z and then doing the same thing but this time letting x=1 and y=0...
  20. G

    Mathematical Basis for Learning Relativity

    Hi, I seem to remember there is a book by Steven Weinberg that gives the mathematical basis for tensor calculus for relativity, but the name escapes me. Anyone know what I'm talking about?
  21. S

    Are super-operators always writable in a basis independent form?

    in particular, i wonder if the trasposition super operator is basis independent or not. We can always write an operator W as \hat{W}=\sum_{i,j} c_{i,j} |i\rangle\langle j| and for the transposed we obtain \hat{W}^T=\sum_{i,j} c_{j,i} |i\rangle\langle j| we obtain a relation true for each...
  22. D

    Basis for the orthogonal complement.

    Homework Statement Let W be the plane 3x + 2y - z = 0 in R3. Find a basis for W^{\perp}Homework Equations N/A The Attempt at a Solution Firstly, I take some arbitrary vector u = \begin{bmatrix}a\\b\\c\end{bmatrix} that is in W^{\perp}. Then I note that W can be rewritten in terms of the...
  23. Matterwave

    Pondering basis vectors and one forms

    So, I've been thinking about this for a while...and I can't seem to resolve it in my head. In this thread I will use a tilde when referring to one forms and a vector sign when referring to vectors and boldface for tensors. It seems to me that if we require the basis vectors and one forms to obey...
  24. S

    Find Basis for Subspace of R^4 Spanned by Vectors

    Hello. First, I'd like to apologize because I don't know where to go ask for homework on linear algebra on the forums so if anyone could please let me know, that would be appreciated. Here's the question: Find a basis for the subspace of R^4 spanned by the given vectors Here's the answer...
  25. N

    What is the position operator in the momentum basis for a given momentum value?

    Homework Statement I need to prove that, <p'|\hat{x}p> = i\hbar\frac{d}{dp'}\delta{p-p'} i.e. find the position operator in the momentum basis p for p'... It's easy to prove that <x'|\hat{x}x> = <\hat{x}x'|x> = x'<x'|x> = x'\delta{x-x'} (position operator in position basis for x') since I...
  26. F

    Partial derivative of radial basis function

    Homework Statement Calculate the partial derivatives (∂f/∂x & ∂f/∂y) Homework EquationsThe Attempt at a Solution really confusing me with the use of the summation and power to 3/2. This is my attempt, most definitely wrong but still tried. ∂f/∂x = x + c1*(2*(x-x1))*([( x-x1 )^2 +...
  27. P

    Unveiling the Physical Basis of Fock Space Dynamics for Chemists

    Hello, I am a chemist and have been working on chemical dynamics. Recently I have started working on some many body interactions. Therein I have found some ideas about Fock Space, Fock Matrix, Fock Space Coherences. These are extensively used to provide characteristic information in...
  28. S

    Confusion regarding the basis of A and the basis of Range of A

    Hello everyone, I am having difficulty understanding the difference between the basis of a subspace A and and the basis of the range of A. My textbook seems to follow the same approach in determining both. So are they essentially the same?
  29. M

    Find a basis for the solution space of the given homogeneous system.

    Homework Statement Find a basis for the solution space of the given homogeneous system. x1 x2 x3 x4 1 2 -1 3 | 0 2 2 -1 6 | 0 1 0 0 3 | 0 The Attempt at a Solution When I reduced to reduced row echelon form i get the following matrix...
  30. N

    Find a basis of U, the subspace of P3

    Homework Statement Find a basis of U, the subspace of P3 U = {p(x) in P3 | p(7) = 0, p(5) = 0}Homework Equations The Attempt at a Solution ax3+bx2+cx+d p(7)=343a+49b+7c+d=0 p(5)=125a+25b+5c+d=0 d=-343a-49b-7c d=-125a-25b-5c ax3+bx2+cx+{(d+d)/2} -->{(d+d)/2}=2d/2=d...
  31. V

    A problem on linear transformation and standard basis

    Problem Given a transformation T : P(t) -> (2t + 1)P(t) where P(t) ϵ P3 (a) Show that transformation is linear. (b) Find the image of P(t) = 2 t^2 - 3 t^3 (c) Find the matrix of T relative to the standard basis ε = {1, t, t^2, t^3} (d) Find the matrix of T relative to the basis β1 = {1...
  32. F

    Algebra, the basis of a solution space

    Homework Statement Find the basis of the solution space W \subset \Re^{4} of the system of linear equations 2x_{1} + 1x_{2} + 2x_{3} +3x_{4} =0 _{ } 1x_{1} + 1x_{2} + 3x_{3} = 0 Homework Equations The basis must span W and be independent. The Attempt at a Solution Solving...
  33. S

    Linear Transformations and Basis

    Homework Statement Show that if { v_1, ... , v_k} spans V then {T(v_1), ... , T(v_k)} spans T(v) Homework Equations The Attempt at a Solution So we know that every vector in V can be written as a linear combination of v_1,...v_k thus we only need to show that {T(v_1)...
  34. L

    Eigenspace and basis of eigenvectors

    Homework Statement Given the matrix 0 1 0 0 0 1 -3 -7 -5 Find the eigenspaces for the various eigenvalues Prove that there cannot be a basis of R3 consisting entirely of eigenvectors of AHomework Equations The Attempt at a Solution The...
  35. N

    Linear Algebra: Vector Spaces & Linear Systems Problem 14

    Homework Statement http://en.wikibooks.org/wiki/Linear_Algebra/Vector_Spaces_and_Linear_Systems/Solutions Problem 14 Can answer be (3,1,2)T (2,0,2)T? also, can I reduce the matrix without transpose? thanks Homework Equations The Attempt at a Solution
  36. M

    Finding a basis for the Kernel of T

    Homework Statement So the question is a map T: R^2x2 ---> R^2x2 by T(A) = BAB, where B = (1 1) (1 1) so i made A = (a c) and T(A) = ((a+b) + (c+d) (a+b) + (c+d))...
  37. B

    Spin 1/2 Basis Change Homework Solution

    Homework Statement This is from my first-quarter graduate QM course. Part 4 of this problem asks me to compute the unitary operator U which transforms Sn into Sz, where Sn is the spin operator for spin 1/2 quantized along some arbitrary axis n = icos\phisinθ + jsin\phisinθ + zcosθ.Homework...
  38. DryRun

    N(A) and R(A) in terms of their basis

    Homework Statement The matrix A = 1 1 1 1 -1 0 1 0 1 2 3 2 Express null space and row space of A in terms of their basis vectors. 2. The attempt at a solution I have found the null space to be: x3 [1 -2 1 0]^T + x4 [0 -1 0 1]^T. But my problem is how do i write the final answer correctly...
  39. B

    Linear Algebra Subspaces Basis

    Homework Statement a) If U and W are subspaces of R^3, show that it is possible to find a basis B for R^3 such that one subset of B is a basis for U and another subset of B (possibly overlapping) is a basis for W. b) If U and W are subspaces of a finite-dimensional vector space V, show...
  40. B

    Finding a Basis for a Vector Space: (1, a, a^2), (1, b, b^2), (1, c, c^2)

    Homework Statement Find a basis for (1, a, a^2) (1, b, b^2) (1, c, c^2) Homework Equations The Attempt at a Solution M(1, a, a^2) + N(1, b, b^2) + K(1, c, c^2) = (0, 0, 0) M + N + K = 0 Ma + Nb + Kc = 0 Ma^2 + Nb^2 + Kc^2 = 0 This is as far as I got. I tried monkeying around with these 3...
  41. P

    Understanding Tangent Space Basis: Proving Intuitively

    I am unable to understand as to how the basis for the tangent space is \frac{\partial}{\partial x_{i}}. Can this be proved ,atleast intuitively? Bachman's Forms book says that if co-ordinates of a point "p" in plane P are (x,y), then \frac{d(x+t,y)}{dt}=\left\langle 1,0\right\rangle...
  42. N

    How do I determine whether a set of polynomials form a basis?

    Homework Statement Are the following statements true or false? Explain your answers carefully, giving all necessary working. (1) p_{1}(t) = 3 + t^{2} and p_{2}(t) = -1 +5t +7t^{2} form a basis for P_{2} (2) p_{1}(t) = 1 + 2t + t^{2}, p_{2}(t) = -1 + t^{2} and p_{3}(t) = 7 + 5t -6t^{2}...
  43. S

    Decide if specified elements are linearly independent, span V, and form a basis

    Homework Statement "In each of the given cases, decide whether the specified elements of the given vector space V (i) are linearly independent, (ii) span V, and (iii) form a basis. Show all reasoning. V is the space of all infinite sequences (a0, a1, a2, ...) of real numbers v1 =...
  44. C

    Linear Algebra - Finding a Basis

    Homework Statement I am having trouble finding a basis in a given vector space. I understand how to find a basis of Rn, just find linearly independent vectors that span Rn But how would i find a basis of the set of 3x3 symmetric real matrices? Or Find a basis of real polynomials of...
  45. B

    Orthogonal change of basis preserves symmetry

    Homework Statement Prove that symmetric and antisymmetric matrices remain symmetric and antisymmetric, respectively, under any orthogonal coordinate transformation (orthogonal change of basis): Directly using the definitions of symmetric and antisymmetric matrices and using the orthogonal...
  46. F

    Is bases the same as basis ? (Simplex Algorithm)

    Homework Statement [PLAIN]http://img193.imageshack.us/img193/3662/unledmcg.png The Attempt at a Solution I rewrote the whole thing in dictionary x_3 = 15 - 8x_1 - 4x_2 x_4 = 7 - 2x_1 - 6x_2 z = 0 + 22x_1 - 12x_2 x_i \geq 0 1\leq i \leq 4 a) So my basis/bases is x...
  47. DryRun

    Is a set of orthogonal basis vectors for a subspace unique?

    Homework Statement Is a set of orthogonal basis vectors for a subspace unique? The attempt at a solution I don't know what this means. Can someone please explain? I managed to find the orthogonal basis vectors and afterwards determining the orthonormal basis vectors, but I'm not sure what the...
  48. X

    2nd basis function for 2nd order ODE

    i have the first solution y_1(t) = t for (1-t)y'' + ty' - y = 0. I need to get the 2nd linearly independent using Abels theorem. the integration is messy but i have it set up (sorry no latex); y_2 = (t) * integral to t ( 1/s^2 * exp( -integral to t (s(s+1) ds) ) ds. Could anyone...
  49. D

    Coordinates relative to a basis

    Homework Statement (In textbook, given a figure, I cannot redraw that figure in this applet, so I shall describe the question in words) I am given a rectangular xy coordinate system determined by the unit basis vectors i and j and an x'y'-coordinate system determined by unit basis...
  50. M

    Gram-Schmidt procedure to find orthonormal basis

    Homework Statement The four functions v0 = 1; v1 = t; v2 = t^2; v3 = t^3 form a basis for the vector space of polynomials of degree 3. Apply the Gram-Schmidt procedure to find an orthonormal basis with respect to the inner product: < f ; g >= (1/2)\int 1-1 f(t)g(t) dtHomework Equations ui =...
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